The present invention relates to a flush valve assembly for use in a water tank of a water closet. More particularly, the present invention relates to a flush valve assembly which has a coaxial design which provides for greater energy throughput thereby causing more energy to be available to remove wastes from the toilet bowl. The greater throughput is achieved by using a greater orifice diameter and including a radius on the inlet side of the valve opening. In addition, the present invention relates in particular to a flush valve assembly having a xe2x80x9ctrip releasexe2x80x9d or xe2x80x9clost motionxe2x80x9d mechanism to effectively disengage the valve opening/closing member from the flush activation member or flush lever.
Toilets for removing waste products are well known. Typically, toilets incorporate three systems that work together to perform the flushing action. Those systems are (1) the bowl siphon, (2) the flush mechanism, and (3) the refill mechanism. Working in concert, these three systems allow the flushing function of the toilet.
Usually, the tank, positioned over the back of the bowl, contains water that is used to initiate the siphoning from the bowl to the sewage line, as well as refilling the bowl with fresh water. When a user desires to flush the toilet, the user pushes down on the flush lever on the outside of the tank, which is connected on the inside of the tank to a movable chain or lever. When the flush lever is depressed on the outside of the tank, it moves a chain or lever on the inside of the tank which acts to lift and open the flush valve, causing water to flow from the tank and into the bowl, thus initiating the toilet flush.
In many toilet designs, water flows both directly into the bowl and is dispersed into the rim of the toilet bowl. The water releases into the bowl rather quickly, with flow from the tank into the bowl typically lasting approximately two to four seconds. The water flows from the rim, down a channel within the sides of the bowl, into the large hole at the bottom of the toilet, commonly known as a siphon jet. The siphon jet releases most of the water into the siphon tube, initiating the siphon action. The siphoning action draws all the water and waste out the bowl, and into the siphon tube. The waste and water continues through the other end of the U-shaped siphon tube through an area know as the trapway, and is then released into the wastewater line connected at the base of the toilet.
Once the tank is emptied or its contents (fresh water) during the flush, the flush valve closes, and a floating mechanism, which has now dropped in the tank to some residual amount, initiates the opening of the filler valve. The filler valve provides fresh water to both the tank and the bowl through separate flows. Eventually, the tank fills with water to a high enough level to cause the float to rise, thus shutting off the filler valve. At this point, the flushing cycle is complete.
However, government agencies have continually demanded that municipal water users reduce the amount of water they use. Much of the focus in recent years has been to reduce the water demand required by toilet flushing operations. In order to illustrate this point, the amount of water used in a toilet for each flush has gradually been reduced by governmental agencies from 7 gallons/flush (prior to the 1950""s), to 5.5 gallons/flush (by the end of the 1960""s), to 3.5 gallons/flush (in the 1980""s). The National Energy Policy Act of 1995 now mandates that toilets sold in the United States can use water in an amount of only 1.6 gallons/flush (6 liters/flush).
In the past, toilet designs have attempted by various methods to comply with this reduced water requirement, but achieving superior flush performance has been difficult. Therefore, it has been found desirable to provide a flush valve assembly which assists the flush operation in meeting the mandated water requirements while at the same time providing for an enhanced and superior flushing operation.
In the crowded art of producing a more reliable, more efficient and more powerful 1.6 gallon (6 liter) gravity toilet, one method to more effectively remove waste from the toilet bowl is to increase the hydraulic energy available during the flushing operation. However, the hydraulic energy available is not enhanced by the typical flush valve design for a coaxial flush valve assembly wherein the effective flow diameter through the flush valve opening is less than the orifice diameter of the flush valve inlet under dynamic conditions. It has therefore been found desirable to provide a flush valve assembly wherein the effective flow diameter of the flush valve opening is close to the inlet orifice diameter under dynamic conditions so as to increase the available hydraulic energy of the flush water.
Current agency requirements further mandate that the activation means or flush lever for the flush valve assembly have a minimum xe2x80x9chold downxe2x80x9d time of 1 second without exceeding the aforementioned total water usage or discharge per flush of 1.6 gallons (6 liters) of water. It has been found that the hydraulic performance characteristics of the flush valve can be significantly enhanced if water can be evacuated from the tank in a dumping time of less than 1 second, preferably 0.5-0.6 seconds. Therefore, it has been further found desirable to provide a flush valve assembly which releases the effect of the activation member or flush lever so that the valve opening can close before the expiration of the mandated minimum xe2x80x9chold downxe2x80x9d time of the flush lever (1 second) without exceeding the total water per flush mandate of 1.6 gallons (6 liters).
It is a general advantage of the present invention to provide a flush valve assembly which overcomes the deficiencies of the flush valve assemblies of the known prior art.
It is also an advantage of the present invention to provide a flush valve assembly which has a greater energy throughput of the flush water in comparison to existing flush valve assemblies to thereby provide more available energy to remove waste from the toilet bowl.
It is a further advantage of the present invention to provide a flush valve assembly which permits a water closet to meet governmental agency requirements which mandate a minimum xe2x80x9chold-downxe2x80x9d duration of the flush activation member or flush lever of 1 second and a maximum water usage of 1.6 gallons (6 liters) per flush.
It is yet a further advantage of the present invention to provide a flush valve assembly which includes a xe2x80x9ctrip-releasexe2x80x9d mechanism which releases the effect of the flush activation member or flush lever on closure of the valve opening so that a predetermined quantity of flush water can be delivered into the toilet bowl very quickly without exceeding mandated agency requirements.
It is still a further advantage of the present invention to provide a flush valve assembly which improves the flow characteristics of the flush water or flow capacity of the flush valve assembly.
This invention relates to a flush valve assembly for use in a water tank of a toilet bowl. This new flush valve assembly is similar to existing coaxial design flush valves used in gravity type water closet toilets which have a flush valve body usually made of plastic and constructed to form a conduit with an inlet end and an outlet end. The inlet and outlet ends allow flush water to pass from the tank or water closet area to the bowl portion of the toilet.
The flush valve assembly of the present invention allows the water tank to which it is installed to hold a predetermined volume of water and to also serve as a conduit to deliver water to the trapway via the passages within the toilet. A first valve member of the flush valve assembly of the present invention includes a base sleeve portion which is secured to the water tank or water closet and an inner cylindrical member extending generally vertically from the base sleeve portion.
A second valve member (flush valve cover or closure component) is coaxially and slidably mounted with respect to the first valve member so that a valve opening is created between the first and second valve members when the second valve member is removed from the first valve member. The second valve member is slidably movable between a first rest position, wherein the second valve member is seated on the base sleeve portion of the first valve member so that water cannot pass through the valve opening, and a second position, wherein the second valve member is removed from the base sleeve portion of the first valve member so that water can pass through the valve opening. The closed position of the valve opening prevents the flow of flush water into the valve until the valve is activated, typically by means of a flush lever assembly. The open position allows the flow of flush water to enter the valve opening and proceed into passages within the toilet to which the tank is attached.
According to one of the specific objects of the present invention, the flush valve assembly of the present invention achieves a greater energy throughput of the flush water, so as to provide more energy available to remove waste from the toilet bowl. In order to obtain this advantageous result, the base sleeve portion of the first valve member has a radiused inlet to thereby optimize venturi flow and increase the water discharge coefficient of the valve opening to approximately 0.95. More specifically, the radiused inlet has a diameter which is approximately 4.5 inches with a radius of xc2xexe2x80x3 incorporated onto the leading edge of the inlet.
In order to reduce the pulling force necessary to close and properly seal the valve opening when the second valve member is moved from its upper second position to its first rest position, an annular sealing member is provided along the outer circumferential surface of the second valve member which rests in an annular indented valve seat provided in an inner peripheral edge of the first valve member when the second valve member is in its first rest position. This annular indented valve seat preferably has a 3 inch diameter.
The second valve member is properly guided and aligned with respect to the first valve member when the second valve member is moved between its first rest and second positions by providing the flush valve assembly of the present invention with a guiding member. This guiding member includes a second cylindrical tube member secured to the second valve member which is fitted over the first cylindrical tube member of the first valve member so that the second valve member is properly guided and accurately aligned with the first valve member when the second valve member is moved between its first rest position and second position.
In order to reduce hydraulic losses and improve flow characteristics of the flush valve assembly, the first valve member also includes structure to minimize flow resistance. This flow resistance minimization member includes a plurality of tapered web members radially disposed between the first cylindrical tube member and the base sleeve position of the first valve member.
When the flush valve cover is in its floated state so that water rushes into the opened flush valve opening, water backflow has a tendency to rise in the confined space of the flush valve cover. In order to restrict further upward migration of the backflow, an annularly inclined baffle member extends from the inner peripheral surface of the outer housing of the second valve member.
Without adequate floatation of the second valve member of the flush valve assembly, the water tank will not drain properly. Therefore, in order to provide floatation of the second valve member when the second valve member is moved from its first rest position to its second position, a floatation cavity is provided in a space between downwardly depending outer wall and inner wall members of the outer housing of the second valve member.
As in typical flush valve assemblies, the second valve closure member is initially moved from its first rest position, wherein the valve opening is closed, to a second position, wherein the valve opening is opened, by means of a flush lever. This flush lever is displaceable by a user between a first rest position and a second position to operatively move the second valve member between its first rest position and its second upper position.
Current agency requirements mandate that the minimum xe2x80x9chold downxe2x80x9d time for the flush lever is 1 second. However, the longer the valve opening remains open before water is evacuated from the tank, the more energy is dissipated during the flush. Therefore, in order to close the valve in less than 1 second, preferably, 0.5-0.6 seconds, and thereby ensure a relatively rapid delivery of a predetermined quantity of flush water without exceeding agency requirements, the flush valve assembly of the present invention includes a xe2x80x9ctrip-releasexe2x80x9d or xe2x80x9clost-motionxe2x80x9d mechanism. This trip release mechanism releases the effect of the flush lever on the second valve member when the second valve member reaches its second upper position so as to return the second valve member to its first rest position prior to the flush lever returning to its first rest position.
In this flush valve assembly, the trip release mechanism includes a cam rod, a pull rod operatively connected to the flush lever and slidably mounted with respect to the cam rod so that the pull rod and the cam rod are movable in response to movement of the flush lever. A trip dog assembly is also incorporated in the trip release mechanism which is capable of engaging the second valve member when the pull rod and cam rod are moved between a first rest position and a second predetermined position and is capable of disengaging the second valve member when the pull rod moves beyond its second predetermined position.
The engaging and disengaging members of the trip dog assembly include wing-like retention members which extend outwardly to engage the second valve member when the pull rod is moved between its first position and the second predetermined position to move the second valve member between its first rest and second positions and which retracts when the pull rod is moved past the second predetermined position disengaging the wing-like retention members from the second valve member so as to allow the second valve member to return to its first rest position.
In order to cooperatively move the cam rod and the pull rod between their first rest and second predetermined positions, the wing-like retention members are engaged within a central depression section of the cam rod. The wing-like retention members are engaged with an annularly inclined baffle member extending from an inner peripheral surface of the outer housing of the second valve member when the pull rod is moved between its first rest position and second predetermined position. When the pull rod is moved past its second predetermined position, the wing-like retention members are retracted thereby disengaging the wing-like retention members from the annularly inclined baffle member to thereby allow the second valve member to return to its first rest position.
In addition, the central tube member of the first valve member includes an annular flange on an end thereof in order to reposition the wing-like retention members to an extended engageable position when the cam rod and pull rod are returned to their first rest position.
By including the xe2x80x9ctrip releasexe2x80x9d or xe2x80x9clost motionxe2x80x9d mechanism in the present invention, the flow characteristics of a flush valve assembly are not only improved but also the flush valve assembly complies with mandated agency requirements.
Various other advantages and features of the present invention will become readily apparent from the ensuing detailed description and the novel features will be particularly pointed out in the appended claims.